Brown's resignation follows that of Citigroup's South Asia CEO, Sanjay Nayar, who has quit the financial services major to join Kohlberg, Kravis, Roberts & Co as its Country Chief.

Citigroup, which received a multi-billion bailout from the US Government on Tuesday, plans to reduce its headcount by over 50,000 but has said that the impact of the job cuts would be minimal in India.